Synthesis and Characterization of Nanosilica Prepared by Precipitation Method

In this work silica nanoparticles were synthesized in a semi-continuous precipitation method. The effects of reaction time, concentration of reactants and pH were investigated on oil absorption and specific surface area (SSA) of synthesized nanoparticles in a full factorial design of experiment (DOE) with three parameters. In this design, each parameter was investigated in two levels. The reaction time and pH were main parameters that affecting on particles oil absorption. BET results showed that all of the three parameters could significantly affect the specific surface area of the product. Morphology and particle size distribution of precipitated nanosilica were investigated using transmission electron microscopy. The particle size of the synthesized silica nanoparticles was observed to be smaller than 20 nm. The average specific surface was found to be of 230 m2/g and average oil absorption 235 g/100 g. The thermogravimetric analysis resultshowed that the total silanol density in the nanosilica was 15 nm-2. J. Color Sci. Tech. 2(2008), 57-66.© Institute for Colorants, Paint and Coatings.